Cover lock



w s. SHERMAN COVER LOCK Filed sept, 30. 1924 Patented Sept. l5, 1925.Y

' WARREN S. SHERMAN, 0F OKLAHOMA CITY, OKLAHTIIDIIIA.l

. COVER LOCK.

Application led September 80, 192,4. Serial No. 740,833.

This invention relates to improvements in lock mechanisms.

The primary ob]ect of this invention is the provision of a lock mechanism `which is particularly adapted for use in connection with manhole covers forvaults and sewers of municipalities, or for any other use, such as meter boxes used on water meters and the like. p

A further object of the invention is the provision of an improved lock which is very simple in construction, and which embodies novel means for gravity actuation to assume a closed position to lock a cover on a frame.

A further object of the invention is the provision of a lock mechanism adapted for use in connection with manhole covers and the like, embodying a simple arrangement of tumblers, and a novel key mechanism which may be yused in connection with the tumblers to hold the same in an unlocked relation to permit lifting of the manhole cover by means of the key, and in such manner that the key may not slip from the tuinhlers when holding them in an unlocked relation.

Other objects and advantages of this invention will be a parent during the course of the following etailed description.

In the accompanying drawing, forming a part of this specification, and wherein similar reference characters designate corresponding parts throughout the several views.

Figure l is a plan View of the manhole cover showing it in position over theopening in its frame, with the improved lock mechanism associated therewith, and a key in the lock mechanism in position the unlocking of the lock mechanism when the key is pulled outwardly.

Figure 2 is a cross Sectional view taken.

substantially on the line 2 2 of Figure 1, although showing the lock and key details in full side elevation. l -M Figure 3 is a View showing the arrangement of tumblers of the lock mechanism, in locked relation to a cover, in the gravity in the county of Oklahoma to permity position which they assume when locking the cover.

Figure 4 is a cross sectional view, show-l the relation which they naturally assume` when the key holds them'insuch position to permit them to assume an unlocked relation; this view being taken substantially on the line 4 4 of Figure 2, although not showing thekey element which is illustrated in Figure 2.

Figure k5 is a longitudinal cross sectional view taken through the manhole cover, frame, and locking mechanism, showing the arrangement of tumblers in their locked relation with respect to the frame of the manhole cover; this view being taken substantially on the line 5 5 of Figure 3.

In the drawing, wherein for the purpose of illustration is shown only a preferred em'- bodiment of the invention, the letter A may generally designate a closuremeinber, of yany approved type, which may be associated f with a frame or receptacle B. f The improved lock mechanism C is preferably carried by' the closure member A, and a key member D is used for unlocking the lock mechanism to permit removalor opening of the closure member A with respect to the frame or receptacle B.

In connection with manhole closures and similar closure, for city vaults, and the like, it is preferable to provide some means for maintaining the closure locked. This lock mechanism must of necessity be simple in character, and automatic in lockingaction, with the tumblers orlocking parts thereof so arranged that they will not become inoperative during the long intervals of time from which they are used. Many complicated lock mechanisms would indeed be impractical for such use, and this invention contemplates the provisionA of a lockmecha-y nism, adaptedkfor this specific use, which" while it may be used in other yfields of endeavor is of relatively simple character and ywill efliciently p perform the duty for which itis adapted.

The closure member A, while it may be of various characters,`

in the preferred instance is a manhole cover, and includes a flat body portion l0 with'beveled marginal edges 11. A central depending reinforcing hub l2 is provided for the body l0, with radially extending reinforcing ribs 13, in conformity with any approved construction. The frame. B is preferably ring shaped in formation, and is adapted for connection in the adjacent ground or cementitious material 15, so that a flange portion 16 thereof may project over the compartment 17 formed by the vault. The manhole cover A is adapted to rest on this flange 16, in accordance with conventional construction. v

Referring to the locking means ofthe manhole cover A, it is preferred to provide a three point locking constructionfor the manhole cover A. On one of the points on the closure A, at the bottom thereof, and adjacent the marginal edge thereof, it is preferred to provide the locking mechanism C. On the other two points, whichmay be distanced 120O on Ieach side of the lock mechanism C, locking lugs 20 may be provided,

which are of L-shaped formation, are connected on the bottom of the manhole cover A, each including the locking tongue 21 which extends beneath the flange portion 16 of the frame B, to prevent direct upward lifting of the manhole cover A when the locking mechanism C, is locked with respect to the frame B. These lugs 2O normally engage the flange 16, or lie therebelow, when the closure A is upon the/frame or receptacle B, and it is necessary to liftthe manhole cover A in direction toward the lock mechanism C to release the locking lugs 2() from their underlying relation with the frame B.

Referring more specifically to the lock mechanism C, the same preferably includes a shaft 30, supported by means of depending lugs or flanges 31, in spaced parallel relation with the planeof the manhole cov-er A; the .shaft 30 being tangentiallyarranged with respect to the cover A, and with the axis thereof below the bottom of the manhole cover A in spaced relation therewith and inwardly of the beveled marginal edge 11 ofthe body 16. Pivotally mounted on the shaft 30 it is preferred to provide four tumblers 33, 34, 35 and 36, although any less or greater number of such tumblers may ,be provided. `These tumblers, while of the VISO same general formation, vary in size, and they are L-shaped in formation, each providing a stop leg 38, extending radially in one direction from theiry hubs 39, and furthermore .each providing a lockingy leg 40 eX- tending in acute angular relation to the stop leg 38, from the hub 39. In normal locking relation on the shaft 30, the stop legs 38 at their outer edges 42 engage the bottom sur- :face 43 of theY body 10 of the manhole cover A', so that the locking ends 44 of the locking legs 40 are spaced below the bottom 43a .of

the closure A a sufficient distance to permit the flange 16 of they frame B to liev in inter-` section relation between the closure body 10 and the locking ends 44. The bottom edges 48 of the locking legs 40, immediately below the locking ends 44 are relatively offset for greater distances from the closure member A, in order to provide a proper conibination'for use in connection with the offset portions of the key D, as will be subsequently described. 1t is to be noted that .the locking edges 50 of the locking ends' 44,

respect to the closure A, these edges 48 will be in stepped relation parallel with the plane of the closure A, asis illustrated in Figure 4 of the drawings.

Referring to the key D, the same is of novel construction, including a shank or f stem 60, with a relatively large flat hand engaging head 61 on one end thereof. On the opposite end of the shank 60, a radially eX- tending bit 62 is provided, which has the successively stepped edges yor surfaces 63, 64, 65 and 66 thereon, with the edge 66 nearest to the handle 61, and the edge 63 most remote. A recess 67 is provided by the bit 62, adjacent the shank 60, in facing relation with the head 61, for a purpose to be subsequently described. s

Referring to the operation of the manhole cover A in connection with the locking means, assuming the manhole to be locked, it is merely necessary to insert the key D in the keyhole slot 68 which/is provided transversely through the cover A. By rotating the key D through 900, the bit 62 will be disposed directly below the locking ends of the tumbler legs 40. Upon lifting of the key B, the recess 67 will now receive the most adjacent lug 31 which supports the shaft 30 from the closure A. This prevents further rotation of the key D in either direction, during the period of time that the key is held in its outward relation. Of course, the key D must be pulled outwardly from the closure member A, after it is turned to theQOo of rotation above mentioned, and in this position the steps 63 to 66 inclusive will respectively engage the bit engaging redges 48 of the tumblers .33 to 36 respectively, and the pulling of the key D outwardly from the manhole cover A moves the bit 62 towardvthe bottom surface of the..

' of said tumblers swingpast theflange 16 of the frame B, into the position illustrated in Figure 4 of the drawings, and l'it canreadily be seen in this view that the .tumblers are in non-interfering relation with respect to the frame. Now by lifting upwardly or outwardlyon the key D, the closure A can be 'tipped away from the frame B at the llO point adjacent the locking mechanism C, and by sliding the same laterally over the frame B, the L-shaped locking lugs 2O may` be removed from their locked relation with respect to the flange 16 of the frame B, so that the closure may be removed from the manhole.

Various changes in the shape, size, and arrangement of parts may be made tothe form of invention herein shown and described, without departing from the spirit of this invention or the scope of the claims.

I claim:

l. In a lock structure the combination of a support having a key hole therethrough, a shaft supported by the support, tumblers pivotally supported by the shaft laterally of the keyhole by gravity adapted to move into locking relation, and when in such locking relation having a plurality of key engaging faces variously spaced from the support, and a key provided with a plurality of relatively offset bit faces adapted to engage the tumblers so that they may be lifted and swung 1 on their pivots into an unlocked relation.

2. In a lock mechanism of the class described the combination of a closure member, a shaft, means supporting .the shaft atk the inside of the closure member in spaced relation therewith, and a plurality of L- shaped tumbler members carried by said shaft each including a stop leg adapted to engage the closure member to limit the locking relation of the tumblers, said tumblers furthermore each including a locking leg adapted to move by gravity to assume a normally locked position, said locking legs in` cluding key engaging faces which are relatively offset from the closure member.

3. In a manhole locking construction of the class described the combination of a frame provided with an opening therein, a cover adapted to be supported by the frame over said opening, lock means for the cover including a pair of spaced lugs and a shaft supported by said spaced lugs below said cover, a plurality of tumblers pivotally carried by said shaft adapted when in locked relation to engage `beneath the frame for' locking the covervmember to the frame, and a key including a bit provided with a recess therein adapted to receive a lug which supports said shaft whereby when the key is in such relation it cannot be laterally turned, and may be used as a handle for removing the cover from the frame with the bit thereof engaging said tumblers to hold them in an unlocked relation.

4l. In a device of the class described the combination of a frame providing an open-k ing therein, a. closure for said opening having a keyhole therein, a lock mechanism for the closure including inwardly extending lugs, a shaft carried by the inwardly eX- tending lugs in spaced relation with the closure, and a plurality of pivotally mounted tumblers of L-shaped formation each including a stop leg and a locking leg, said stop legs adapted to normally engage the cover incident to gravitational movement of the locking leg, said locking legs including key engaging faces relatively offset in stepped relation, and a key including a shank and a bit on an' end thereof, said bit having a recess therein adapted to receive a lug which supports said shaft after the key has been inserted in the keyhole of said cover and pulled outwardly into said position, said bit when in such position adapted to have the same engagel said keyengaging faces of the locking legs of the tumblers whereby to hold said tumblers in an unlocked relation with respect to said frame, and whereby the key may be used as a handle for pulling the cover off said frame.

5. In a locking mechanism of the class described the combination of a support, a shaft carried by the support in spacedrelation therewith, and substantially L-shaped tumblers pivotally carried by said shaft each including a stop leg and a locking leg of greater weight than the stop leg, said stop leg being in such relation to the support that the locking legs when overbalancing the same will cause the stop legs to engage the support to limit the locking position of said locking legs.

WARREN S. SHERMAN. 

